diff --git a/Leetcode problems/Happy Number b/Leetcode problems/Happy Number
new file mode 100644
index 00000000..a02efa68
--- /dev/null
+++ b/Leetcode problems/Happy Number	
@@ -0,0 +1,13 @@
+// https://leetcode.com/problems/happy-number/
+
+class Solution {
+    public ListNode middleNode(ListNode head) {
+        ListNode f = head;
+        ListNode s = head;
+        while (f != null && f.next != null) {
+            s = s.next;
+            f = f.next.next;
+        }
+        return s;
+    }
+}